<form method="get" class="form-horizontal" action="/documents.html">
<div class="form-group">
    <div class="col-sm-4">
    	<input type="text"  name="q" class="input-medium search-query" placeholder="<?php echo Yii::t('helpdesk','Keyword'); ?>" value="<?php echo !empty($keyword)?$keyword:null; ?>" >
    	<input type="submit" class="btn btn-success" style="height:26px; padding: 0 5px;" value="<?php echo Yii::t('helpdesk','Search'); ?>">
    </div>
</div>
</form>